By St. Symeon, Archbishop of Thessaloniki
Question 55
From where comes the tradition of the Presanctified Liturgy? And why is it imperfect? And how is it that it is not performed during the other fasts? As some say, it was not handed down to us from the other fasts.
Answer
The Presanctified Liturgy has come to us from the successors of the apostles, as both ancient prayers and tradition testify. And we take it for certain that it owes its origin to the Apostles, having first been compiled for the sake of this fasting period, so that in the days of mourning we could mourn and not celebrate, as was said before by others. On the other hand, it was accepted by the Fathers so that we could receive grace and not be left completely without communion of the Mysteries of Christ, and through it the sacred propitiatory prayers. We perform this rite around the ninth hour, observing the rule of fasting, which prescribes eating once, in the evening. We are sanctified by it by looking with our eyes, together with our minds, on the Lord, who is held by the priests, and offered as propitiation for us and given to those worthy of His communion. At the same time, we must eagerly fall to the ground before Him, ask for forgiveness of our errors and remember all believers - that is, during the entrance, when the priest holds the Lord at his head, since these are already completed Mysteries and the true body and blood of Christ. If before they are perfected the gifts are worthy of honor, since they are a type and dedicated to God, then much more so after they are perfected at the Liturgy by divine grace through the ritual, and have truly become the body and blood of Christ.
Source: "Answers to Gabriel of Pentapolis". Translated by John Sanidopoulos.